Global trends in milk quality: implications for the Irish dairy industry

The quality of Irish agricultural product will become increasingly important with the ongoing liberalisation of international trade. This paper presents a review of the global and Irish dairy industries; considers the impact of milk quality on farm profitability, food processing and human health, examines global trends in quality; and explores several models that are successfully being used to tackle milk quality concerns. There is a growing global demand for dairy products, fuelled in part by growing consumer wealth in developing countries. Global dairy trade represents only 6.2% of global production and demand currently outstrips supply. Although the Irish dairy industry is small by global standards, approximately 85% of annual production is exported annually. It is also the world's largest producer of powdered infant formula. Milk quality has an impact on human health, milk processing and on-farm profitability. Somatic cell count (SCC) is a key measure of milk quality, with a SCC not exceeding 400,000 cells/ml (the EU milk quality standard) generally accepted as the international export standard. There have been ongoing improvements in milk quality among both established and emerging international suppliers. A number of countries have developed successful industry-led models to tackle milk quality concerns. Based on international experiences, it is likely that problems with effective translation of knowledge to practice, rather than incomplete knowledge per se, are the more important constraints to national progress towards improved milk quality.


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and a period of record international milk prices. In global terms, the Irish dairy industry is small, producing 5.2 million tonnes (0.94% of global production). However, the industry exports approximately 85% of annual production and is a major contributor to the national economy. The industry is also the world's largest producer of powdered infant formula.

b. World dairy demand
There is a growing global demand (an increase of 3% globally, but more than 10% in some developing countries, and 15% in China) for milk and other dairy products. Global competitiveness is also fuelling new uses for milkbased ingredients, rising demand for cheese variety, an increase in niche product markets and increased product shelf life (Blayney et al. 2006;Dairy Australia 2007). The very sharp rise in world dairy prices from late 2006 (Berry and Hogan 2007) was driven, largely, by the strong global demand for dairy products, leading to record farmgate prices (exceeding €0.35/l) for manufacturing milk in Ireland (Lavery 2007). By early 2008, the price spike had peaked for commodities such as milk powders and butter, with market prices rapidly returning to more normal levels (Irish Farmers Monthly 2008). In wealthy countries, there have been substantial shifts in demand for dairy products. In the EU, the demand for cheese and other milk products (such as fresh cream, specialised milk protein for the food industry and other dairy ingredients) has risen, and butter consumption has fallen. Approximately 40% of milk within the EU is now consumed as cheese (European Commission 2006). In the US, milk consumption is falling (concurrent with a rise in the consumption of carbonated drinks) (Huth et al. 2006), whereas butter consumption has remained steady (Henning et al. 2006). In recent years, there has been a substantial drive to retain market share in the face of non-dairy substitutes. Functional foods (such as probiotic milks, yogurts and fermented dairy drinks) represent one strategy to capitalise on growing consumer awareness of the role of dairy components in health and vitality. There have also been rapid technological advances in dairy processing (Figure 1), particularly the use of membrane technology (allowing the separation of milk components) for industry applications (Henning et al. 2006 Figure 1: The conversion of milk, by a range of processes, into a variety of dairy products and food ingredients. (1) Skim milk is comprised of protein, other solids (lactose, minerals) and water; (2) Standardised milk, with a fat content adjusted by the addition of skim or cream (European Commission 2006).
of this process, milk protein concentrates (principally liquid or spray-dried milk protein) are increasingly used as food ingredients (for example, in frozen desserts, bakery and confectionary products) and for pharmaceutical use (Blayney et al. 2006). A general shift towards non-dairy substitutes has also been avoided, due to the rising price of substitute fats and proteins (Dairy Australia 2007).
In low-income countries, dairy products, including dry milk powders, remain luxury goods for many consumers (Blayney et al. 2006). Therefore, in Africa, the Americas and Asia demand is fuelled in large part by increasing consumer wealth. Per capita milk consumption is rising, but often from a very low base (Fuller et al. 2007; United States Department of Agriculture 2007). There has been a marked change in dietary patterns throughout Asia, as a consequence of higher incomes and changing consumption patterns (Berry and Hogan 2007), leading to shifts towards 'western' foods including dairy products (Fuller et al. 2006;Pingali 2006). Growing consumer income is also driving increased consumption of liquid milk in China (consumption increased from 3.2 kg to 8.8 per capita between 2002 and 2005), India, Russia and the Ukraine, and an increasing global demand for high-quality dairy products, particularly cheese (International Dairy Federation 2007a,b). In a recent study, Fuller et al. (2007) has highlighted the influence of education, advertising and convenience, as well as the increasing sophistication of the retail sector, in the growth of milk products in the Chinese market. Food safety is emerging as an attribute demanded by Chinese consumers (Wang et al. 2008). The Chinese dairy industry has been in crisis since September 11 2008, after news reports highlighted melamine contamination of milk and milk products. Melamine (also known as tripolycyanamide) is an industrial chemical that is used in laminates, glues, adhesives, and plastics. When added to (sub-standard) milk, melamine increasing the nitrogen concentration, suggesting a false increase in protein concentration. Melamine contamination carries a significant public health risk; by September 22, Chinese authorities had reported that 52,857 children had been treated for renal complications, and at least four children have died (Chan et al. 2008). There has been a rapid international response, including a decision by the EU to ban the importation of all baby food containing Chinese milk (Parry 2008

THe ImPorTANCe oF mIlK quAlITy
Milk somatic cell count (SCC) is a key measure of milk quality, reflecting the health status of the mammary gland and the risk of non-physiological changes to milk composition. It is also the key component of national and international regulation for milk quality, udder health and the prevalence of clinical and subclinical mastitis in dairy herds. Milk quality is important, with impacts on human health, milk processing and on-farm profitability: Farm profitability: There are a range of economic • consequences of mastitis and mastitis management, relating to treatment, production losses, culling and changes in milk quality. Increased SCC is associated with reductions in milk yield. Milk processing: High SCC milk adversely affects • cheese production, as a result of reduced curd firmness, decreased milk yield, increased fat and casein loss in whey and compromised sensory quality. High SCC milk also affects the quality of pasteurised liquid milk and reduces its shelf life.
Human health: High cell count milk is not associated • with direct risks to human health. However, there are a number of indirect risks as a result of poor farm hygiene, antibiotic residues and the presence of pathogenic organisms and toxins in milk.

Definition
Raw milk quality encompasses criteria relating to composition (butterfat, crude protein, lactose, milk solids etc) and hygiene (total bacterial count, somatic cell count). Of these, SCC is the most important single indicator of milk quality, reflecting the health status of the mammary gland and the risk of non-physiological changes to milk composition (Hamann 2005). It is also the key component of national and international regulation for milk quality (van Schaik et al. 2002). An udder quarter is considered healthy if it has an SCC < 100,000 cells/ml and is free of mastitis pathogens (Dohoo and Meek 1982;Hamann 2005). An elevated SCC is indicative of mastitis (inflammation of the mammary gland), generally caused by presence of infectious microorganisms (Hamann 2005).
In response to consumer demands, the processing industry also has a growing interest in additional milk quality parameters relating to environmental considerations, animal welfare and food safety and traceability (Andersen 2007;Nousiainen et al. 2007;Refsholt et al. 2007).

The impact of milk quality on farm profitability
There are a range of economic consequences from clinical and subclinical mastitis, relating to treatment, production losses, culling and changes in milk quality (Hasala et al. 2007). Collectively, these factors have a substantial impact on the farm business. To this point, however, there has been little consistency among a range of studies in the reported costs of mastitis and the benefits from mastitis management. This variation partly reflects regional differences, for example in labour costs. In addition, Hasala et al. (2007) highlight important methodological differences between reported studies, which make comparison difficult.
To overcome this difficulty, these authors propose an economic framework to consistently assess the economic effects of mastitis and mastitis management. Increased somatic cell counts are associated with reduced milk yield. Estimates of milk loss from high SCC range from 0.3 to 1.8 l/cow/day, depending on the stage of lactation and SCC level (Hortet and Seegers 1998;Green et al. 2006). A slightly lower reduction in yield was measured, after accounting for the effect of dilution on SCC among high-yielding dairy cows (Green et al. 2006). There appears to be no loss of milk yield in cows with SCC up to approximately 100,000 cells/ml; therefore, there are unlikely to be economic benefits from driving cow SCC below this level (Green et al. 2006).

The impact of milk quality on milk processing
Milk quality has a substantial, adverse impact on milk processing. Mastitis is associated with an influx of inflammatory cells (hence, 'high somatic cell count' milk), and increased activity of heat-stable proteases and lipases, leading to a breakdown of casein and milk fat (Santos et al. 2003;Barbano et al. 2006). Herds with mastitis problems are also at increasing risk of antibiotic residue violation, as a result of increased antibiotic usage (Ruegg and Tabone 2000;van Schaik et al. 2002).
There are a range of adverse effects from the use of high SCC milk in the production of cheese, including reduced curd firmness, decreased cheese yield, increased fat and casein loss in whey and compromised sensory quality (Ma et al. 2000). When used in the production of cottage cheese (made from acid coagulation of milk, rather than rennet), high SCC milk was also associated with increased proteolysis during refrigerated storage (Klei et al. 1998). These effects would adversely affect the yield of milk protein concentrate (MPC), which consist of casein-type and whey proteins (Blayney et al. 2006). Mastitis also affects the quality of pasteurised liquid milk and reduces its shelf life (Ma et al. 2000).

The impact of milk quality on human health
There is no evidence that high cell count milk is directly associated with adverse effects on human health (National Mastitis Council 2001). However, high cell counts are associated with increased indirect risks, including poor farm hygiene, antibiotic residues and the presence of pathogenic organisms and toxins in milk. Heat-stable enterotoxins produced by Staphylococcus aureus in milk from infected cows have been implicated in cases of food poisoning (National Mastitis Council 2005a).

GloBAl TreNDS IN mIlK quAlITy
The EU milk quality standard (SCC not exceeding 400,000 cells/ml) is generally accepted as the international export standard. Among established international suppliers, particularly in Europe and Australasia, there has been a progressive fall in somatic cell counts. In Norway, the national BMSCC (bulk milk somatic cell count) is 115,000 cells/ml; in Ireland in 2004, this figure was approximately 250,000 cells/ml. Among emerging dairy suppliers, there has been a rise in milk quality as a consequence of industry investment and a focus on export success. Argentinean exporters now exceed international standards in the quality, hygiene, safety and traceability of dairy products.

Legislative issues
Within the European Union, EU Council Directive 92/46/ EEC lays down the health rules for the production and placing on the market of raw milk, heat-treated milk and milk-based products. These include a requirement that raw milk has a somatic cell count not exceeding 400,000 cells/ ml, based on the geometric average of monthly samples over a period of three months. All dairy products sold in the European market (both local and imported) must meet these standards.

b. Emerging international suppliers
Among emerging dairy suppliers, there has been a rise in milk quality as a consequence of industry investment and a focus on export success. To illustrate, consider dairy producing countries in South America. In the 1970s and 1980s in Chile, unofficial information suggests that the average BMSCC was >500,000 cells/ml. Since the mid-1990s, there has been substantial investment in the dairy industry to improve production systems, milk quality and milk products. Further, a scheme of penalty and bonus payments was introduced in 1993, based on BMSCC and Peer reVIewed bacterial counts. By 2000, the average BMSCC had fallen to 330,000 cells/ml (Kruze 2000 cited by Tadich et al. 2003). Until the early 1990s in Argentina and Brazil, the development of standards for milk safety and quality was managed by government. Although these standards were rigorous, government often did not have the capacity to rigorously enforce compliance. Following deregulation in 1990, there was substantial industry reform including the imposition of private milk standards for both the farm and processing sectors. In 2006, Argentina exported 215,000 tonnes of whole milk powder and 58,000 tonnes of cheese (International Dairy Federation 2007a), and exporters now exceed international standards in quality, hygiene, safety and traceability (Farina et al. 2005). In Brazil, the industry has mainly focused on local demand (Dairy Australia 2007), where quality demands have been lower. UHT milk, which dominates the liquid milk market in Brazil, can be made from lower quality raw milk provided stabilisers are used (Farina et al. 2005).

TACKlING mIlK quAlITy CoNCerNS
Based on experiences from a number of countries, it is likely that problems with effective translation of knowledge to practice, rather than incomplete knowledge per se, are the more important constraints to national progress towards improved milk quality. A number of national programmes have now been developed to address milk quality issues, including an industry-led programme in Australia called Countdown Downunder. This programme has been built around the concept of capacity-building, which, in simple terms, is about increasing the abilities and resources of individuals, organisations and communities to manage change. The Countdown programme is built around the six steps of the action planning cycle, which includes identifying needs, setting goals, planning action, taking action, reviewing progress, and learning and re-planning. A broad range of resources have been developed to support these steps, including farmer short courses, farm guidelines, mastitis action plans, mastitis focus reports and milk quality awards.

Constraints to progress
Mastitis research has been conducted for many decades (Noordhuizen and Hogeveen 2005), and many aspects of mastitis are now very well-understood (Radostits et al. 2007). The 5-point mastitis control programme was first devised in the late 1960s (Neave et al. 1966), and remains the basis for infectious mastitis control. A further five points, specifically addressing the control of environmental mastitis, were added later (Radostits et al. 2007 Problems with effective translation of knowledge to practice, rather than incomplete knowledge per se, are likely to be the more important constraint to national progress towards improved milk quality (Doherty 2007;Valeeva et al. 2007 there were significant reductions in clinical mastitis and somatic cell counts following the implementation of well-specified mastitis control plans in problem herds. These authors concluded that 'there may be sufficient knowledge to reduce the current incidence of mastitis …, but that its application, and also further education, knowledge transfer and motivation may remain essential to achieving improved mastitis control' (Green et al. 2007); and In recent years, somatic cell count problems have been • resolved on many farms in Ireland following a detailed farm investigation and follow-up support (O'Grady and More unpublished). In addition, recent work has qualified the influence on variable milk quality premiums on observed milk quality. Financial incentives (a penalty programme for low quality milk combined with a premium programme for very high quality milk) are a key driver for improvements to milk quality (Schukken et al. 1992;Nightingale et al. 2008). A review of payment systems for ex-farm milk has recently been completed (International Dairy Federation 2006). with an initial situation assessment followed by field implementation, based on an understanding of the current situation, implementation of new tools, and international best-practice in mastitis control (van der Zwaag et al. 2005). The programme is being implemented by a multidisciplinary team, through a series of veterinary practices. A wide range of tools are being used, based on best-practice in other countries, including the use of a 'milk mirror' (a once-yearly specialist farm visit), structured and nationally-consistent protocol, a monthly mastitis update for veterinarians and monthly financial feedback to farmers (money saved from reduced mastitis) (van der Zwaag et al. 2005). b. Australia Australia's national mastitis and cell count control programme, Countdown Downunder, was created in 1998 to help farmers meet new quality standards, improve farm profitability and protect export markets (Dairy Research and Development Corporation 2001). The programme was instigated following the implementation of EU Directive 92/46/EEC (Anon. 1992) and the implementation of industry-wide targets seeking 90% and 100% of the milk supply from Australian dairy farms with BMSCC <250,000 and <400,000 cells/ml, respectively (Dairy Research and Development Corporation 2001). After the first five years of the programme, just under 94% of herds achieved a cell count of less than 400,000 cells/ml (Brightling et al. 2005). The current phase of the programme (2004)(2005)(2006)(2007) is focusing on the translation of the knowledge and skills of the whole farm team (farmers and advisers) into continuous improvement and risk management on farm (Brightling et al. 2005). The Countdown programme has been built around the concept of capacity-building which, in simple terms, is about increasing the abilities and resources of individuals, organisations and communities to manage change (Cooperative Venture for Capacity Building 2004). It is now considered a more effective means of extension delivery to support change, compared with both the transfer of technology, 'top-down' approach, and the 'bottom-up' approach based on farmer participation and group extension methods (Nettle et al. 2003). Capacity-building is an area of active research (Macadam et al. 2004; including the establishment of a Cooperative Venture for Capacity Building, with the aim to build capacity to enable rural industries to become more sustainable and competitive), and detailed resources are available (McKenzie 2007). The Countdown programme focuses on the capacity of farmers to address (that is, make strategic and progressive improvements to) mastitis and milk quality. To achieve this, they need a good understanding of the principles underpinning mastitis control, the skills and confidence to achieve best practice on farm, and resources and services to support change on farms (Brightling et al. 2005). The programme is built around the six steps of the action planning cycle, which includes identifying needs, setting goals, planning action, taking action, reviewing progress, and learning and re-planning (Nettle et al. 2006; Figure 2). A broad range of resources have been developed to support these steps, including farmer short courses, farm guidelines, mastitis action plans, mastitis focus reports and milk quality awards. The purpose of the short courses has been to stimulate change on-farm, by repeatedly challenging farmers to 'close the gap' between current and best practice, by encouraging the use of triggers for the early detection of udder health problems, by promoting a team approach between farmers and their dairy advisers, and helping farmers to be comfortable about using the services of farm advisers (McKenzie 2007). The action planning process has the potential to stall at a number of points on the action planning cycle, as highlighted in Figure 3. Based on recent research (Nettle et al. 2006), support for sustainable change on-farm is reliant upon:

Examples of national mastitis control programmes
Mastitis action plans that fit the needs of the farm • business; Jointly-agreed goals by all members of the farm team • with day-to-day responsibility for udder health and milk quality; and, Regular review of the farm situation by farm managers • (Nettle et al. 2006).
L e a r n a n d r e -p la n Id en ti fy ne ed s Review progres s T a k e a c t io n P la n a c ti o n

Take action
Are the first steps actionable?
Are key practice changes being fully implemented? Are we measuring key performance outcomes?
L e a r n a n d r e -p la n Id en ti fy n ee ds Review progre ss T a k e a c t io n P la n a c ti o n

CoNCluSIoNS
The Irish dairy industry is well-positioned to benefit from the increased global demand for dairy products. Milk quality will increasingly contribute to competitive advantage for the Irish dairy industry, for a range of reasons relating to human health, milk processing and farm profitability. A number of countries have achieved substantial improvements in milk quality, highlighting models to tackle milk quality concerns. Ireland would greatly benefit from an industry-led programme, with defined objective national targets, focusing on the capacity of farmers to make strategic and progressive improvements to mastitis and milk quality. laying down the health rules for the production and placing on the market of raw milk, heat treated milk and milk-based products. Official Journal of the European Communities L268, 1-32. 14 September 1992. Anon. (1996)